Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

*LCRS Endocrinology Y1* > Hypothalamo-adenohypophysial Axis > Flashcards

Hypothalamo-adenohypophysial Axis Flashcards

1
Q

How large is the pituitary gland?

A

Size of a pea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the pituitary gland also known as?

A

Hypophysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does the pituitary gland sit?

A

Under hypothalamus below brain in the Sella Turca (pituitary fossa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two sections of the pituitary?

A

Anterior: adenohypophysis
Posterior: neurohypophysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the clinical relevence of the sella turca?

A

Any pituitary tumour will be restricted by the walls of the bony cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the embryological origins of the pituitary?

A

Anterior: Buccal cavity has extension that begins growing upwards
Posterior: Downward movement of material from the hypothalamus
Two tissues fuse and lose contact w/buccal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the area that lies between the top of the pituitary stalk and the hypothalamus, and what is it?

A

Median Eminence - essentially a mass of arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the neurohypophysis mainly consist of?

A

Nerve axons, w/their cell bodies in the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where does the median eminence receive its blood supply from?

A

Superior hypophysial artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the capillaries in the median eminence known as?

A

Primary capillary plexus (fenestrated, lies outside of blood-brain barrier)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where does blood from the primary capillary plexus go?

A

Through portal veins which run down the pituitary stalk and terminate in the adenohypophysis in the secondary capillary plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where does the blood go after leaving the adenohypophysis?

A

Into the cavernous sinus then out via jugular veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the action of hypothalamic control over the pituitary:

A

Hypothalmic neurones secrete chemicals from their axons.
NOT NEUROTRANSMITTERS
STRAIGHT INTO BLOOD
Axons lie on the primary capillary plexus in the median eminence.

Portal veins carry messengers into anterior pituitary, where they bind to target cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the five main types of anterior pituitary cells?

A 
Somatotrophs
Lactotrophs
Thyrotrophs
Gonadotrophs
Corticotrophs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What hormones do somatotrophs produce?

A

Somatotrophin (growth hormone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which anterior pituitary cells produce LH and FSH?

A

Gonadotrophs

17
Q

Give two examples of Protein hormones produced by the adenohypophysis:

A

Somatotrophin

Prolactin

18
Q

Give three examples of glycoprotein hormones produced by the adenohypophysis:

A

Thyrotrophin

LH and FSH

19
Q

Give an example of a polypeptide hormone produced by the adenohypophysis:

A

Corticotrophin

20
Q

What do somatotrophs target?

A

General body tissues, particularly the liver

growth hormone

21
Q

What does prolactin target?

A

Breasts in lactating women

22
Q

What does corticotrophin target?

A

Adrenal cortex

23
Q

What are the stimulatory/inhibitory hormones for Somatotrophin production?

A

Stim: Growth hormone releasing hormone
Inhib: Somatostatin

24
Q

What are the stimulatory/inhibitory hormones for Prolactin production?

A

Stim: Thyrotrophin releasing hormone
Inhib: Dopamine (dominant over TRH)

25
Q

What two hormones do Thryotrophin stimulating hormone stimulate?

A

Prolactin

Thyroid stimulating hormone

26
Q

What are the two stimulatory hormones of ACTH?

A

Vasopressin

Corticotrophin releasing hormone

27
Q

What type of hormones stimulate hormone release from the anterior pituitary?

A

Releasing hormones

28
Q

What happens when Somatotrophin reaches the liver?

A

It stimulates the production of Insulin-like Growth Factor I and II (IGF1&2)

29
Q

Where does IGF1 bind, and what effect does it have?

A

Receptors on Bone and Muscle

More protein synthesis
Increased gluconeogenesis
Stimulation of lipolysis to lead to increased fatty acid production
Cartilage and bone growth

30
Q

Describe the negative feedback loop that inhibits Somatotrophin:

A

Direct IGF1 to the pituitary reduces secretion of somatotrophin
(or indirect via hypothalamus)

31
Q

What is a physiological stimulus of Growth hormone secretion?

A

Hypoglycaemia, since IGF stimulates Gluconeogenesis etc.

32
Q

What does Prolactin inhibit?

A

LH production
- as mainly present during lactation, so prevents periods and suppresses sexual behaviour, as mother would not want to become pregnant again

33
Q

How is the synthesis of new milk started for the next suckling period?

A

Suckling stimulation of nipple stimulates afferent neural pathway to the hypothalamus.
This inhibits dopamine production, so more prolactin is released

*LCRS Endocrinology Y1* (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions